Worksheet for Morgan/Carter Laboratory #16 Plant Diversity II: Seed Plants

Transcription

1 Worksheet for Morgan/Carter Laboratory #16 Plant Diversity II: Seed Plants BE SURE TO CAREFULLY READ THE INTRODUCTION PRIOR TO ANSWERING THE QUESTIONS!!! You will need to refer to your text book to answer some of the questions on this worksheet. Procedure 2. In the box below, sketch a drawing of two different gymnosperm plants on display and name them. Results 2. Are there any reproductive structures present on these plants? Phylum Examples Characteristics/Comments Coniferophyta Ginkophyta Cycadophyta Gnetophyta

2 Discussion 1. What are the key characteristics of all gymnosperms? 2. What is the ecological role of conifers in the forest ecosystems? 3. What economically important products are provided by conifers? 4. What economically important products are produced by the other gymnosperms? Figure 16.1 Use different colors to circle which structures are haploid and diploid.

3 Lab Study B: Pine Life Cycle Procedure 1. Pine Sporophyte a. Examine the pine branch and notice the arrangement of the leaves in a bundle. A new twig at the end of the branch is in the process of producing new clusters of leaves. Is this plant haploid or diploid? b. Examine the small cones produced at the end of the pine branch on this specimen of others in the lab. Recall that cones contain clusters of sporangia. What important process occurs in the sporangia. c. Locate an ovulate and a pollen cone. Elongated male pollen cones are present only in the spring. The small, more rounded female cones (which look like miniature pine cones) are produced on the stem tips in the spring and are called ovulate cones. d. In the box below, sketch a drawing for future reference. 2. Male gametophyte a. Examine a longitudinal section of the pollen cone on a prepared slide. The sacs are the microsporangia. Microsporophytes (microspore mother cells) within the sporangia divide by meiosis. Each produces four haploid microspores, which then develop into pollen grains. b. Observe a slide of pine pollen. c. In the box below, sketch a drawing for future reference.

4 2. Female gametophyte a. Examine the longitudinal section of a young ovulate cone on a prepared slide. Note the ovule (containing the megasporangium) on the upper surface of the scales. Diploid megasporocytes (megaspore mother cells) contained inside will produce haploid megaspores, the first cells of the gametophyte generation. d. In the box below, sketch a drawing for future reference. Discussion 1. What is the function of the wings on the pollen grain? 2. Why is wind-dispersed pollen an important phenomenon in the evolution of plants? 3. Are microspores produced by mitosis or meiosis? 4. Describe the structure and function of a seed. 5. Can you think of at least two ways in which pine seeds might be dispersed?

5 6. One of the major trends in plant evolution is the reduction in the size of the gametophyte. Describe male and female gametophyte in terms of size and location. Ex. 16-2: ANGIOSPERMS Lab Study A: Flower Morphology Procedure 1. Examine fresh flowers of different species of angiosperms and look at their structures. (Figure 16.2 for reference) 2. In the box below, draw a picture of one of the flowers and label the parts. Record your results in Table 16.3 below. Table 16.3 Features Plant #1 Flower Plant #2 - Flower Number of Petals Number of Sepals Absent parts Color Scent (+ or -) Nectar (+ or -) Shape Special features Predicted Pollinator (see Key to Pollination)

6 Lab Study B: Pollinators Procedure Using the key above, classify the flowers in Table 16.3 based on their floral traits and method of pollination. Discussion 1. Review the Key to Pollination and describe the characteristics of flowers that are adapted for pollination by each of the following agents: a. Wind b. Hummingbird c. Bat Lab Study C: Angiosperm Life Cycle Procedure 1. Pollen Grain The Male Gametophyte a. Examine a prepared slide of the Lilium and observe the stamens. Try to observe a single anther, the formation of microspores. Sketch a drawing of what you observe in the box below:

7 2. Development of the Female Gametophyte a. Examine a prepared slide of the Lilium ovary and locate the ovules. Try to observe the megaspores, only one of which survives. Sketch a drawing of what you observe in the box below: 3. Pollination and Fertilization d. Examine the pollen after 30 minutes and 60 minutes. Draw what you observe in the box below: Results 1. Review the structures and processes observed in the angiosperm life cycle below and use different colors to circle the haploid and diploid structures of the life cycle.

8 Results 3. Record the results of the pollen germination slides in the table below: Name of Plant Pollen After 30 Minutes After 60 Minutes Discussion 1. What part of the life cycle (e.g. gender and phyte) is represented by the mature pollen grain? 2. How does the female gametophyte in angiosperms differ from the female gametophyte in gymnosperms? 3. Do you think that all pollen germinates on all flower stigmas? How might pollen germination be controlled by plants to limit which plants it will fertilize? Lab Study D: Fruits and Dispersal Results 1. In the Table below, write the name of five different fruits and how their seeds might be dispersed. Fruits Dispersal Method

9 Discussion 1. How might dry fruits be dispersed? 2. Describe the characteristics of an achene, drupe and berry. REVIEWING YOUR KNOWLEDGE 1. Complete the table below comparing the features of different types of plants. Features Moss Fern Conifer Angiosperm Dominant gametophyte or sporophyte? Water needed for fertilization? Vascular Tissue (xylem and phloem)? Homosporous or heterosporous? Seeds? Pollen grains? Fruit? 2. What is the role of each of the following structures in seed plants? pollen grain microsporangium

10 flower carpel seed fruit endosperm 3. Plants have evolved a number of different characteristics that attract animals and ensure pollination, but what are the benefits to the animals in this relationship? 4. Why is internal fertilization required for living on land as opposed to water?